DESIGN AND TESTING OF A SMALL ORCHARD TRACTOR DRIVEN BY A POWER BATTERY

ABSTRACT An electric orchard tractor with a power battery and transmission driven by dual motors was developed. The output shafts of the walking and power take-off (PTO) motors are connected by a wet clutch, which controls whether the two motors are coupled or independent. When the load of the walking or PTO motor exceeds its output torque, the two motors are driven by power coupled by the wet clutch to meet the power demand. According to the heavy-load working conditions of ploughing and rototilling, the power battery capacity and working duration targets of 15 kW and 4 hours/charge were set. A prototype 15 kW electric orchard tractor was manufactured and assembled, and its performance was assessed. A bench test showed that the tractor’s maximum PTO output power was 13.9 kW and a field rototilling test showed that its maximum continuous working time was 4.5 hours. Thus, the prototype electric orchard tractor met the design goals and requirements of for orchard operations.